Current status of calcium channel-blocking drugs after Q wave and non-Q wave myocardial infarction.

The calcium channel blockers are useful in treating many cardiovascular disorders. Due to their anti-ischemic and spasmolytic properties, the cardioprotective effects of these agents have been studied in the setting of acute myocardial infarction. This paper will review this application with respect to limitation of infarct size, reduction of mortality, and incident morbidity rates. Of the agents currently available for clinical use, nifedipine has been studied most extensively. This agent shows no beneficial effects and its use can, in fact, be harmful in this setting. Of the few trials that have been conducted with verapamil, none have shown a preventive effect on death, reinfarction, or postinfarction angina. Both verapamil and diltiazem might limit infarct size although further confirmation is required. At the present time, diltiazem is the only agent shown to have short- and long-term benefits on clinical outcome in patients with acute myocardial infarction. The success of prophylactic diltiazem is, however, critically dependent on proper patient selection. In particular, those patients with non-Q wave infarction, normal left ventricular function, or both can be expected to derive the greatest benefit in terms of reduced mortality and incident morbidity.